1. Field of the Invention
The invention relates to forming anastomoses between hollow anatomical bodies, such as blood vessels. More particularly, the invention relates to using magnetic force to form anastomoses between such vessels while attempting to minimize the amount of material that is located in the blood flow path.
2. Description of Related Art
Despite the considerable advances that have been realized in cardiology and cardiovascular surgery, heart disease remains the leading cause of death throughout much of the world. Coronary artery disease, or arteriosclerosis, is the single leading cause of death in the United States today. As a result, those in the cardiovascular field continue to search, with varying degrees of success, for new and improved manners of treating cardiovascular disease.
Coronary artery disease is currently treated by interventional procedures such as percutaneous transluminal coronary angioplasty (PTCA), coronary stenting and atherectomy, as well as surgical procedures including coronary artery bypass grafting (CABG). The goal of these procedures is to reestablish or improve blood flow through occluded (or partially occluded) coronary arteries, and is accomplished, for example, by enlarging the blood flow lumen of the artery or forming a bypass that allows blood to circumvent the occlusion. What procedure(s) is used typically depends on the severity and location of the blockage. CABG is typically performed when interventional procedures have been unsuccessful or, for one reason or another, are not available options for a given patient. When successful, these procedures restore flow within the treated vessel(s) and feed blood to myocardial tissue that had previously been insufficiently perfused.
Another proposed treatment places the target vessel, e.g., a coronary artery, in direct fluid communication with a heart chamber containing blood, for example, the left ventricle. Blood flows from the ventricle into a conduit that is in fluid communication with the artery; as such, this treatment may be described as a ventricular bypass procedure. Benefits of this procedure include obviating the need to manipulate the aorta, for example, as is done when a side-biting clamp is used in a typical CABG procedure to create a proximal anastomosis between the bypass graft and the aorta.
The most challenging aspect of CABG (as well as many other procedures that requiring forming an anastomosis) is connecting the graft vessel to the target vessel in a secure, fluid-tight manner. This is conventionally done by hand using suture that is passed through the tissue of the two vessels to create a handsewn connection. The small diameter of coronary vessels (typically 1 mm to 4 mm) makes creating these handsewn anastomoses highly technical and time consuming. The difficulty in forming the sutured anastomosis is exacerbated when access to the target vessel is restricted or limited as compared to open-chest CABG, for example, as in minimally invasive or percutaneous procedures. A number of other medical procedures also require the attachment of hollow anatomical bodies (by sewing or otherwise) and therefore involve the same or similar considerations, for instance, treating peripheral vascular disease or injury and creating arteriovenous shunts.
Many various anastomotic couplings have been proposed in the art, although none has performed well enough to receive any significant level of acceptance in the field. Exemplary problems experienced by some of these couplers include damage to the graft or target vessel wall, for instance, due to piercing, penetrating or overly compressing the tissue, and failure to produce repeatable results. Additionally, producing an anastomotic coupler that creates and maintains a patent connection has been somewhat elusive and hard to achieve.
One coupling technology with promising results based on early clinical success is Ventrica, Inc.'s MVP™ (Magnetic Vascular Positioner) anastomotic connector system. The reader's attention is directed to U.S. Pat. No. 6,352,543 to Cole, which discloses various magnetic connector configurations
Accordingly, there is a need in the art for methods and devices for forming a reliable anastomosis between hollow bodies in a relatively quick, easy and repeatable manner.